864
FXUS65 KBYZ 100638
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
1238 AM MDT THU SEP 10 2026
KEY MESSAGES
- ELEVATED TO CRITICAL FIRE WEATHER CONDITIONS TODAY. WINDS WILL
BE STRONGEST OVER THE FOOTHILLS WEST OF BILLINGS.
- A PATTERN CHANGE BRINGS COOLER TEMPERATURES AND MULTIPLE CHANCES
FOR PRECIPITATION FRIDAY THROUGH THE WEEKEND, INCLUDING
MOUNTAIN SNOW.
- CHANCE (40-60%) FOR FOOTHILLS LOCATIONS TO SEE THEIR FIRST FROST
MONDAY MORNING.
DISCUSSION
NEXT 7 DAYS...ANOTHER DAY OF SUMMER LIKE WEATHER IS IN STORE FOR
OUR REGION BEFORE WE GET OUR FIRST TASTE OF FALL. TODAY, AHEAD OF
THE COLD FRONT, HIGH TEMPS WILL BE 10 DEGREES ABOVE AVERAGE FOR
MOST OF US WITH HIGHS IN THE 80S. RELATIVE HUMIDITY WILL ALSO
REMAIN QUITE LOW AS THE PREVAILING WIND THROUGH THE LOW LEVELS
WILL STILL BE WESTERLY (DOWNSLOPE). THERE IS ALSO A GOOD SIGNAL
FOR GUSTY WINDS THROUGH THE DAYTIME HOURS TODAY. THE STRONGEST
WINDS ARE FORECAST IN THE FOOTHILLS / GAP AREAS TO THE WEST OF
BILLINGS WHERE GUSTS IN THE 30S MPH WILL BE COMMON THIS AFTERNOON.
THE OTHER AREA OF HIGHER WIND GUSTS WILL BE FAR SE MONTANA AS THE
EXPOSED PLAINS WILL ALLOW FOR INTERRUPTED WINDS GUSTING UP TO 30
MPH. THESE CONDITIONS WILL RESULT IN ELEVATED TO CRITICAL FIRE
WEATHER ACROSS THE CWA WITH THE FOCUS IN THOSE REGIONS MENTIONED
ABOVE DUE TO THE STRONGER WINDS.
OUR FIRST REAL FALL COLD FRONT WILL MOVE THROUGH THURSDAY NIGHT
INTO EARLY FRIDAY MORNING BRINGING IN MUCH COOLER TEMPERATURES.
WHILE MUCH OF THE REGION WILL BE 10 DEGREES ABOVE AVERAGE TODAY,
THE HIGHS ON FRIDAY WILL LIKELY BE AROUND 5 TO 10 DEGREES BELOW
AVERAGE. THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TO
ACCOMPANY THE FROPA AS WELL AS LINGER THROUGH THE DAY FRIDAY,
ESPECIALLY IN THE WESTERN PART OF THE CWA. WE WILL THEN REMAIN
UNDER THE MAIN UPPER LEVEL JET STREAM THROUGH THE WEEKEND WHICH
WILL ALLOW FOR TEMPS TO CONTINUE TO COOL OFF AS WELL AS ALLOW FOR
SEVERAL CHANCES FOR PRECIPITATION.
EXACT TIMING, COVERAGE, AND AMOUNTS OF PRECIP ARE STILL IN
QUESTION. WHILE MOST OF THE MODELS AND THEIR ENSEMBLES DO HAVE
GOOD AGREEMENT AROUND THE SYNOPTIC SCALE PATTERN, THE MESOSCALE
FEATURES ARE STILL YET TO BE AGREED UPON. REGARDLESS OF WHAT
THE DETAILS ARE, COOL TEMPS AS WELL AS ROUNDS OF SHOWERS SHOULD
BE ANTICIPATED. WITH THESE COOLER TEMPS THERE IS A DECENT CHANCE
OF THE FIRST FROST OR FREEZE FOR SOME LOCATIONS. THE COLDEST AREAS
WILL LIKELY BE THE FOOTHILLS REGION FROM THE PARADISE VALLEY UP
THROUGH JUDITH GAP. THESE AREAS HAVE A 40-60% CHANCE OF A FROST
(36F) MONDAY MORNING AND A 20-40% CHANCE OF THEIR FIRST FREEZE.
ACROSS THE ENTIRE CWA, NO MATTER HOW COLD IT IS, THE COOLEST
TEMPERATURES OF THE SEASON SO FAR ARE LOOKING VERY LIKELY THIS
WEEKEND.
NATURALLY, THE CHANCE FOR PRECIP BEHIND A COLD FRONT IN SEPTEMBER
INVITES THE QUESTION OF MOUNTAIN SNOW. THE LOWEST SNOW LEVEL OF
THE WEEKEND STILL HAS VERY LARGE DISCREPANCIES. OVER THE
MOUNTAINS OF SOUTH CENTRAL MONTANA THE NBM 10-90 PERCENTILE RANGE MONDAY
AM HAS SNOW LEVELS RANGING BETWEEN 5KFT AND 8.5KFT. IT IS
IMPORTANT TO NOTE THAT ANY SNOW ACCUMULATIONS, REGARDLESS OF THE
SNOW LEVEL, WILL BE CONFINED TO ABOVE 9KFT. THIS COULD RESULT IN
SOME TRAVEL IMPACTS ON THE BEARTOOTH PASS, PRIMARILY ON SUNDAY. NO
MATTER WHAT THE PRECIP TYPE IS THOUGH, THE COMBINATION OF WET AND
COLD CONDITIONS WILL RESULT IN HAZARDOUS BACKCOUNTRY CONDITIONS
FOR THE ENTIRE WEEKEND.
AS WE GO INTO FIRST HALF OF NEXT WEEK, THERE IS A GOOD SIGNAL
THAT WE WILL REMAIN IN AN ACTIVE PATTERN. SEVERAL SHORTWAVES COULD
PIVOT THROUGH THE REGION BRINGING REPEATED ROUNDS OF PRECIP AS
COOLER THE AVERAGE TEMPERATURES HANG AROUND. WMR
AVIATION
06Z TAF/AVIATION DISCUSSION...VFR CONDITIONS WILL PREVAIL THROUGH
THE PERIOD. WESTERLY WINDS GUSTING 15-30 KTS, ARE EXPECTED AGAIN
IN THE FOOTHILLS (KLVM, K6SO, K1KM) AND NEAR THE DAKOTAS BORDER
(KBHK) TODAY. COLD FRONT WILL BRING A WIND SHIFT LATE EVENING
THURSDAY. WINDS IN THE GENERALLY WIND SHADOWED BIGHORN FOOTHILLS
(KSHR) WILL LIKELY GET GUSTY (25KTS) FROM THE WEST AHEAD OF THIS
WIND SHIFT AFTER 03Z. CHAMBERS
PRELIMINARY POINT TEMP/POPS
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 087 053/069 049/066 046/065 043/064 041/065 043/065
0/U 01/B 31/B 55/T 40/B 00/B 01/B
LVM 086 048/073 043/066 039/064 037/063 034/066 040/067
0/N 03/T 31/N 56/T 41/B 00/U 01/B
HDN 090 049/072 045/070 043/070 039/064 036/069 039/068
0/K 00/B 31/B 55/T 50/B 00/U 00/B
MLS 088 056/071 047/066 046/068 044/060 039/066 043/068
0/U 01/B 21/E 65/T 61/N 00/U 11/B
4BQ 089 056/075 047/071 049/073 044/064 039/069 044/071
0/U 00/U 31/B 64/T 41/B 00/U 10/B
BHK 089 052/074 041/067 041/067 041/061 035/068 040/072
0/N 00/B 12/W 76/T 72/W 10/U 11/B
SHR 088 051/075 041/071 044/072 037/065 035/070 039/069
0/U 02/U 31/B 43/T 31/U 00/U 11/B
BYZ WATCHES/WARNINGS/ADVISORIES
MT...RED FLAG WARNING IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS
EVENING FOR ZONES 123-124-127-133.
WY...NONE.
WEATHER.GOV/BILLINGS
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